Previously, there is a known fuel injection valve that opens and closes injection holes formed in a housing through reciprocation of a needle to inject fuel, which is placed in the housing. For example, the patent literature 1 recites a fuel injection valve that includes a housing, which includes a plurality of injection holes having different inner diameters that are set depending on an installation location of a spark plug relative to an internal combustion engine.
In the fuel injection valve of the patent literature 1, the injection holes are respectively formed such that an inner diameter of an inner opening of the injection hole formed in an inner wall of the housing is equal to an inner diameter of an outer opening of the injection hole formed in an outer wall of the housing, and a cross sectional area of the injection hole is constant from the inner opening to the outer opening. In general, in the injection hole, which is formed such that the cross sectional area of the injection hole is constant from the inner opening to the outer opening, a distance (hereinafter referred to as a spray penetration length) from the injection hole to a location where the fuel injected from the injection hole reaches is determined based on a ratio between the inner diameter of the injection hole and a wall thickness of a member, in which the injection holes are formed. Therefore, in the fuel injection valve of the patent literature 1, when the spray penetration length needs to be adjusted at the respective injection holes, a process, which changes the wall thickness in conformity with the respective injection holes, is required. Furthermore, when the inner diameter of the inner opening of the injection hole is reduced for the purpose of atomizing the fuel, the ratio between the inner diameter of the injection hole and the wall thickness is increased to cause an increase in the spray penetration length. Therefore, there is a high possibility of that the injected fuel collides against a piston and/or a cylinder block, which forms a combustion chamber, to cause an increase in the amount of particulate matter generated.